This invention pertains to a latch mechanism for detachably securing an elongated draft member or tongue in what is known as a transport position in which the tongue is parallel to and immediately adjacent one side rail of the elongated frame of a bale handler which is capable of supporting a plurality of bales of agricultural product, such as hay and straw or the like, one of the preferred uses of the invention being for the transportation of so-called round bales. While working in a field and especially while loading such a bale handler, it is commonplace to have the draft member disposed at an angle to the frame of the handler so as to permit ready access to both ends of the frame such as when loading or unloading the bales therefrom. This is known as the so-called field position. The draft member is pivotally connected at one end to a side rail of the frame of the handler intermediately of the ends thereof.
One latch mechanism for detachably securing the draft member in the transport position adjacent and parallel to a side rail of the frame of the handler as indicated above is disclosed in prior U.S. Pat. No. 3,952,895 to Campbell, dated Apr. 27, 1976, and assigned to the assignee of the present invention. In this prior patent, there is an elongated frame on the handler which is capable of being pivoted relative to a horizontal axis located intermediately of the opposite ends of the frame so as to facilitate loading and unloading of the frame with bales. An elongated draft member is pivoted at one end to an intermediate portion of one of the side rails of the frame. A hydraulic cylinder unit is employed to move the draft member about a substantially vertical axis, toward and away from the transport position adjacent the side rail of the frame. Part of the latch mechanism comprises a spring-loaded pin projecting from the draft member and engageable in an opening in a side rail to prevent relative vertical movement between the draft member and the frame. Another part of the latch mechanism is located adjacent the vertical pivot axis for the draft member and is in the form of vertically aligned pairs of holes formed in vertically spaced apart mounting plates on the draft member and the frame adapted for insertion of a retaining pin through a pair of the aligned holes to prevent relative horizontal movement between the draft member and the frame. The insertion of the retaining pin is a separate manual operation which is both time consuming and inconvenient.